Einstein, who had already developed the light-quantum theory, knew the inadequacy of Maxwell's theory in the microscopic sphere. Therefore, in writing his paper on special relativity, he had to set up the light-velocity postulate independently of the relativity postulate in order to make the electromagnetic foundation of physics compatible with Planck's radiation formula. This constitutes the essential difference between the theories of Lorentz-Poincare and Einstein. The reason that students of the history of special relativity hitherto overlooked this fact lies in a crucial error contained in Einstein's "Autobiographical Notes". The correction, introduced first in the German edition of 1955, revealed that the first core ingredient of Einstein's research program was "thermodynamics". Einstein's theory survived the quantum revolution, while Lorentz-Poincare's did not. Some educational implications are also discussed.